Cod sursa(job #1935047)
Utilizator | Data | 21 martie 2017 23:10:49 | |
---|---|---|---|
Problema | Aria | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.46 kb |
#include <iostream>
#include <fstream>
#include <cmath>
#include <iomanip>
using namespace std;
ifstream fin("aria.in");
ofstream fout("aria.out");
long double x[100002]={0},y[100002]={0};
int main()
{
long double ras=0;
int i,n;
fin>>n;
for(i=0;i<n;i++)
fin>>x[i]>>y[i];
x[n]=x[0];
y[n]=y[0];
for(i=0;i<n;i++)
ras+=(x[i]*y[i+1]-y[i]*x[i+1]);
ras=fabs(ras/2.0);
fout<<setprecision(5)<<ras<<'\n';
}